Northrop Development
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Northrop N-156 family program             Last update 03-12-2020

The US Air Force was engaged in a run to obtain higher and higher performances and armament load from its new fighters up to the sixties, with the consequence
sof increasing complexity
, increase in airframe weight, spiralling maintenance costs and necessity for long runways.
Northrop studies on lightweight fighters begun in the mid fifties with the N-102 "Fang" project, which was not built. This had no resemblance to the future N-156/F-5.

  Photo: Northrop
        Northrop N-102 Fang mock-up with fictitious serial 22777

Small, lightweight engines with enough power were a problem, solved wth the availability of General Electric's J-85 beginning 1955. A new project was started with the
designation N-156 and implied a family of aircrafts, consisting in a ground based fighter (N-156F), a carrier-borne fighter (N-156N) and a trainer (N-156T, later TZ-156).

The US Air Force needed at the time a new supersonic trainer to replace the Lockheed T-33A; it issued in May 1955 an operational requirement for what was to be selected
and designated Northrop T-38A.

Northrop went on with development of the fighter version as a private venture, although the US Air Force was not interested in the proposal for its own use, but the
aircraft might have been of interest to allied nations.
Official presentation to the USAF of both the single- and double-seater was in January 1956.

Construction go-ahead (with company funding) was given early 1958. On 27-05-58 (rather unusually) an research and development contract with the US Department of
Defense was formalized allocating almost USD 50m (32m to Northrop and 18m to General Electric) for 3 aircrafts
and 1 static test airframe to Norair,
the division of the new Northrop Corporation now responsible for building aircrafts and missiles
.

                 
                Mock-up with fictitious 56 (Fiscal Year) 156 (project number) serial.     Photo: Northrop

Official first prototype roll-out followed at Hawthorne on 31-05-59. Representatives of forty allied nations attended to the ceremony.
Licence production discussions were held with European aircraft builders: Fokker of the Netherlands, SABCA of Belgium and FIAT of Italy but their governments selected
the Lockheed F-104G as their new fighter. Discussions were also held with Australia and the United Kingdom without results.

     Photo: Northrop
                         Colour picture of Northrop N-156F mock-upin March 1957

                                                            Drawing: Northrop
                                              
Northrop publicity drawing, rocket assisted take-off!!!!!!!!!!!!!!!!!!

             Photo: Northrop
     First prototype 94987
, before being selected by USAF, with (future) gun bay open

             
           Photo: Northrop
                         All armament to be carried (serparately) by the N-156F on show

First flight of the first prototype, serial 59-4987, took place on 30-07-59 (without any Air Force insignia and markings) at Edwards AFB,
where the aircraft had been transferred, going supersonic on the first flight despite the low thrust of the installed General Electric YJ-85-1 engine.

   Photo: Northrop
Overflight of Edwards AFB still in company colours (Norair on tail, no nationality markings), Freedom Fighter F-5 inscription

                                                 Photo: Northrop
                                        Nose inscription before selection by USA

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F-5A Freedom Fighter development - Northrop/USAF trials

            
        The second protoype at an Edwards AFB open-day with Sidewinders and a full load of tanks
.
        No
nationality or US Air Force markings yet painted as the type had not been officially accepted.

  Photo: Northrop
Flight tests proceeded smoothly, a USAF project test pilot flying the aircraft from th
e third flight for preliminary evaluation.
No cannon armament was originally fitted, but tests with 20mm underwing podded cannons took place.

            
                    First prototype with GAM-83 Bullpup missile underwing.
            Photo: Northrop
 Air-to-air and (non USA, quite unusual!) air-to-ground missiles were taken in consideration as
armament in 1960:
Nord AA.20 (a-a) AS.20 (a-g), Nord AA.25, AS.25 and AS.30, without follow on.


The first prototype with
nose probe, Nord AS.30 underfuselage, AS.20 underwing
and AIM-9B Sidewinder missiles at wingstip
in 1962.                  Photo: unknown

More powerful General Electric YJ-85-5, with afterburner, replaced the early version after 32 test flights; the second prototype was foreseen to fly
in January
1960.

          Photo: Northrop
Intensive armament trials took place: live 250/500/750 pounds bombs and napalm canisters were dropped, 2.75 inch rockets were fired,  AIM-9B
Sidewinder air-to-air missiles were carried on the wingtips,
a "special missions" (nuclear) bomb mock-up under the fuselage.

                                      
Photo: Northrop
                                          The third prototype on a test flight, note long nose pitot tube.


US Air Force tests at Edwards AFB were concluded with great satisfaction in August 1960, but this did not lead to an Air Force change of mind. No order for
its own use was placed and it seemed the the programm was going to be stopped, so the construction of the third prototype remained incompleted.


Official interest in the aircraft was renewed when the Kennedy administration beginning 60's decided to suppy it allies with a low-cost fighter under the Military
Assistance Program FX; a competition was held involving the Freedom Fighter, the Douglas A-4 Skyhawk and the Lockheed F-104H, a simplified version of the
Lockheed F-104G, this last being preferred by the Air Force.


The Northrop F-5A was anyhow selected as the winner, officially announced on 23-04-62, receiving the USAF designation Northrop F-5A Freedom Fighter in
August 1962.
The third prototype, designated Northrop YF-5A, was completed and flew on 31-07-63, being fully representative of production aircrafts. Both
earlier prototypes were later brought up to YF-5A standard

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F-5B Freedom Fighter

          Photo: Northrop
This picture clearly shows the external diffence between the Northrop F-5B (serial 38443,
the company's demonstrator) and the Northrop T-38A trainer.
First flight of the two-seater Northrop F-5B was on 24-02-64; it was accepted ba the USAF and declared operationa on 30-04-64, some four
months earleir than the single-seater. The experience with the Northrop T-38 trainer was fruitful.

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F-5A Freedom Fighter development - US Army trials
The US Army's wish to operate its own supportforce led in January 1961 till July 1961 to trials for the possible selection of a jet aircraft. This would have operated
in the Forward Air Control and the Close Air Support role operating from uniproved airfields near front lines. Initial factory tests were held on a grass runway at
Hughes airfield, Culver City, not far from the Hawthorne factory, followed at NAS Jacksonville and NAS Pensacola.


Two Fiat G-91R-3s, two G-91R-4s, one G-91T-1, two Douglas A-4D-2 (A-4B) Skyhawks and the two Freedom Fighters prototypes (59-04987/988) participated
at Fort Rucker Army Base to the trials.

    Photo: Northrop
Bombs armed Northrop YF-5A 94987 (without guns) in company with its competitors, 
Fiat G-91R-3 and Douglas A-4B.


    Photo: Northrop Grumman Corp.
        First Northrop YF-5A 94987 on an US Army test carrying two underwing tanks.

The Northrop aircraft was preferred by the Army, but the project was cancelled due to US Air Force fierce opposition.

             
            Soft ground trials
at Pensacola in June 1961: the second Freedom Fighter prototype with
            larger tires on the main and two-tires on the front landing gear, later removed. Trials
            included landing in 1300 ft/396m on grass and taking off with a maximum load in less
            than 2'500 ft/762m.
USAF inscription was replaced by "Army" in September 1961 for
            additional tests at Pensacola NAS.


                                 
    Photo: Northrop
                                  Second prototype
Northrop YF-5A 94988 seen on a grass runway, with external fuel tanks
                                  and
single-tire wheel  on the front landing gear.

Production lines

             Photo: Northrop
                    Construction line for the Northrop F-5s in 1960s
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F-5NN Freedom Fighter - US Navy



A certain interest for the Northrop N-156 was shown after World War II by the US Navy, as only their piston engined aircrafts
could be handled by small escort carriers, at the time used mainly as aircraft transport carriers..


The first Northrop (paper) light fighter project
for the US Navy was the N-156NN or PD-2706 show in November 1955, but
 interest died when the Navy retired end 1950's these carriers.

Drawing of the poroposed Northrop N-156NN